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Tuesday, 31 December 2013

Every reptile house has at least one species of giant snake on show, and usually these are Burmese Pythons Python bivittatus, Reticulated Python P. reticulatus, Common Boa Boa constrictor, or Green Anaconda Eunectes murinus. At Bristol, there is a different, and much less often seen species, the Amethystine Python Morelia amethistina (note spelling). There is 2 pair on show, each around 3m long.

Saturday, 21 December 2013

Moving on from the boas, we come to the, in many ways similar, pythons. Except for the introduced Burmese pythons in Florida, pythons are restricted to the warmer parts of the Old World, with various species ranging from Africa across into Australia. Here at the zoo there are two species on show in the Reptile House, the Savu Island and Amethystine pythons, plus Royal pythons that are used in education talks, but it is the Savu Python that I will begin with.

Monday, 9 December 2013

The other boid species currently on show at Bristol are Cuban boas, Chilobothrus (formerly Epicrates) angulifer. These are fairly typical medium-sized (for boas) snakes, reaching around 3m usually, although a length of 4.8m is on record. They are confined to Cuba, and are currently classed as Near Threatened by the IUCN. The chief threats are human persecution and deforestation, but at present at least it is not as threatened as some of its relatives on other West Indian islands.

Saturday, 30 November 2013

In common with most zoos, the majority of Bristol’s snake collection consists of boas, pythons, and various North American colubrids. These snakes are about the easiest to maintain in captivity, as just about all of them either feed on rodents and other mammals in the wild or can be trained to east them in captivity. Maintaining the various specialist invertebrate, fish, or amphibian in captivity is much more time consuming, so people whose ideas of the potential variety of snake species and ecological specialisations are derived from zoo or pet snakes are often surprised at what snakes can do.

Tuesday, 19 November 2013

The other venomous snake that we have on show at Bristol is the first snake encountered as you enter the Reptile House, a fine specimen of the Mangrove or Gold-Ringed Cat Snake, Boiga dendrophila. Despite their English name, Mangrove snakes are more commonly found in lowland rain forest than in actual mangroves, but they certainly deserve their specific name, as they are highly arboreal. Unlike the rattlesnakes and cobras, they are classed as opisthoglyphous (“back-fanged” in common usage), as although they have venom instead of specialised fangs to inject it at the front of their mouths, They have up to 3 enlarged teeth further back in their mouths, and rely on chewing to introduce venom to their prey. Opisthoglyphous snakes are usually less venomous to humans, and for Mangrove snakes no human fatalities have been reported, but some people have more extreme reactions than others and snakes from different parts of their huge range in South East Asia probably vary in toxicity, so it is unwise to handle them without protection.

Friday, 8 November 2013

After a long break, the review of the various species held at Bristol continues with the snake collection. Bristol Zoos’ reptile department has bred several snake species over the years, but the main focus at present is on Asian turtles and amphibians.

Thursday, 19 September 2013

The last of the passerines currently on show at Bristol Zoo is the Chesnut-backed thrush, Geocichla dohertyi. A native of the Lesser Sunda islands, Lombok, and Timor in Indonesia, it is already extinct on Lombok and is declining, mainly as a result of deforestation and local bird trapping, in the rest of its range. As a result it is classed by the IUCN as Near Threatened, and the wild population is estimated at around 25,000 individuals. The captive population, both in zoos worldwide and in private hands, is probably under 200.

Friday, 6 September 2013

Officially with the English name of Red-billed Leiothrix, I still prefer the original name Pekin Robin for Leiothrix lutea. Belonging to the same family (Leiothicidae) as last weeks’ Sumatran Laughingthrush, it is a much smaller bird, about the same size as a European Robin (15cm beak to tail length) and with a very sweet song. As a result, it featured heavily in the cage bird trade for many years, although imports to Europe are now banned under EU rules.

Friday, 23 August 2013

Widespread throughout Asia are a group of medium sized to large passerines, the laughingthrushes, Garrulax spp., with at least 50 species. Despite their name, they are not considered especially close to the true thrushes, Turdus spp., instead being placed currently in a separate family Leiothricidae, generally considered close to the various species of babblers in the Timaliidae.

Saturday, 17 August 2013

﻿ The only species of the crow family that Bristol currently has in its collection is a bird with (until recently) a rather mysterious distribution. The Azure-Winged Magpie is know from only two parts of the world, the Iberian peninsula in Europe, and eastern Asia, with no known populations in between. This was so confusing a picture that for a long time it was believed that the birds in Spain and Portugal originated very recently as escaped sailors pets, brought back by Spanish or Portugese navigators to the Far East in the 16th or 17th centuries, but it is now known that they are relicts of a much more widely spread population, which diverged from the Asian birds at least a million years ago. The European birds do look somewhat different, being rather smaller and lacking a white end to the tail, but otherwise look and behave the same as the Asian birds. The Bristol zoo birds are the Asian form, Cyanopica cyana. The European birds have been classed as a separate species, C.cooki, but this is not yet on the official lists.

Saturday, 10 August 2013

Moving on from starlings, one of the most musical birds in our collection can be seen in the Forest of Birds, where we have a pair of White-Rumped Shama, Copsychus malabaricus. These birds have an extensive range through India and south East Asia, and have been divided into numerous subspecies. In addition, they have been introduced to Hawai’i and Taiwan, where they are considered invasive and a possible threat to native species.

Thursday, 1 August 2013

The last, and rarest, of the starlings we have at Bristol is one of the most beautiful of the group, the Bali Starling (or Mynah) Leucopsar rothschildi. Only scientifically described in 1912, it is endemic to the island of Bali in Indonesia, and is the only surviving endemic vertebrate. Bali is densely populated, and the resultant habitat destruction resulting of conversion of its native habitat for agriculture means that it is classed as Critically Endangered by the IUCN.

Unlike most starlings, which often feed on the ground, Bali Starlings feed by gleaning through the canopy, searching for fruit and insects. They nest in holes in trees, both those excavated by other birds and natural cavities. As with most starlings, male and female are identical, and the song of the male is a series of wheezes and crackles.

Saturday, 20 July 2013

Living in the forest of birds, where they usually make their presence known by a typical metallic call from among the foliage, is a small group of Asian Glossy Starlings, Aplonis panayensis. Aplonis starlings are widespread throughout the islands of SE Asia, with at least 21 species described, several with endemic subspecies, and further three are known to have become extinct, with a fourth, the Pohnpei Starling A. pelzelni, either extinct or on the verge of extinction.

Saturday, 29 June 2013

Kicking off a new series on the various passerines we have at Bristol we begin with one of the more widely kept and exhibited of the passerines to be seen in zoos around the world, the Superb Starling Lamprotornis (formerly Spreo) superbus. Starlings on the whole make good aviary exhibits, being fairly large for passerines and many species feed on both fruit and animal matter, which makes feeding them easier. In the past supplying a variety of live insects for aviary birds, especially when they were raising young, was quite a chore, and usually expensive, but modern live food commercial companies now exist and an increasing number of insectivorous species are being bred successfully. Starlings posed less trouble than more specialised smaller passerines, as the animal part of their diet could be supplied in the form of baby mice, which were a lot easier to breed in bulk than say crickets.

Friday, 14 June 2013

Some recent visitors to the zoo will have noticed that the old prairie dog enclosure now appears to be empty. More careful (and watchful) visitors, especially at quieter times, will see that we have added a new species to the collection, a group of young European souslik, Spermophilus citellus. These in many ways resemble in their behaviour the American prairie dogs, but are much smaller, about the size of a half grown guinea pig (cavy if you are an American reader). There are actually six pairs in the enclosure for now, but with luck by next year the numbers will have considerably increased.

Monday, 10 June 2013

One of Bristol Zoo's signature animals is Okapi. We were the first UK zoo to hold them and also the first to breed them, and practically all of the world's captive Okapi have Bristol Zoo animlas in their family tree. We were therefore especially pleased that we now have a new addition to the zoo, with the birth of the latest calf a few week's ago. Here is the press release from t6he Bristol Zoo website,a nd the accompanying photo of the mother and calf:

Saturday, 25 May 2013

Now flying in the woods opposite the zoo, the Speckled Wood Pararge aegeria is one of our commonest butterflies, and is familiar to anyone who has gone for a woodland walk in most parts of the country. It has an amazingly long flight season, and can be seen from now until September, even though an individual butterfly probably only lives for a week at most.

Tuesday, 21 May 2013

After a break of a few weeks, I have decided to start a new occasional series this year on the various butterflies that I come across on walks or in my garden, and despite the late spring and bad breeding season last year a few have finally started to show up. I will start off with a very pretty little butterfly that is often mistaken for one of its relatives, the Green-Veined White Pieris napi. Although much the same size as the cabbage pest the Small White, it can be distinguished by the heavy green veining on the underside of the hind wings.

Saturday, 27 April 2013

This year, as various interesting plants in the zoos gardens come into their best season, I will be writing posts on their natural (and garden) history. Kicking off the series, our Camellia Walk (between Twilight World and the Reptile House) has several large and old Camellias in full blossom. They started some weeks ago, but the cold spring has held them back.

Saturday, 13 April 2013

Now on show in the marine invertebrate section of Bug World is a small group of unusual jellyfish, the Upside-Down Jellyfish Cassiopea sp. As you might guess from their name, these creatures spend their adult lives resting upside down on the sea bottom, instead of swimming in the supper surfaces of the sea as most jellyfish do although if disturbed they can swim with contractions of the bell as with their more mobile relatives.

Cassiopea is only found in shallow waters with high light levels on the sea floor, usually lagoons, mud flats and mangrove swamps. They do this because like corals they harbour algae in their tissues, which provide food to their host by photosynthesis. As well as their algae, they can also feed on smaller organisms as they retain the nematocysts, the stinging cells which predatory jellyfish use to kill prey, although to humans at least the sting is very weak. The group of jellyfish they belong too has modified their internal anatomy – the primary mouth at the center of the bell is closed and instead secondary openings into the digestive cavity open at the edge of the body.

A different morph - colour is due to symbiotic algae

Jellyfish (Scyphozoa is the technical name) exhibit alternation of generations during their life cycle. The adult reproductive phase is called the medusa, and the adults are either rmale or female. Eggs and sperm cells are released into the digestive cavity and expelled through the mouths into the surrounding water, where they meet and the egg is fertilised. After spending a short period in the plankton, the egg become a planula larva (so called because it resembles a planarian flatworm) only a few millimetres long, which settles on a suitable substrate to become a polyp with tentacles that feeds and grows for a few months. How the planula selects a suitable substrate is not entirely clear – in the Bermudan species C. xamachana they seem to prefer the shady side of decaying Red Mangrove leaves. Presumably other species (the genus is found worldwide) have similar requirements, but I have not seen much study of differences between them. At this point they also acquire their symbiotic algae through feeding on plankton.

Lateral view showing the feeding arms

After growing for a few months, the small polyp begins to strobilate. This involves budding off tiny medusae, which then settle down on the sea floor to grow into the adult phase over the next few months. As neither the adults nor the polyps are especially mobile, how many actual species of Cassiopea exist is subject to debate and is probably more than are currently recognised – they certainly seem to come in different colour morphs in parts of their range but whether these are actually separate species is unclear. They do not seem to have many natural enemies – possible specialised flatworms prey on them as they do on corals, but I have not found any specific documentation on line on these. None of the forms is currently listed as threatened, and this is unlikely to change in the near future.

Friday, 29 March 2013

People often use the term ‘bug’ to mean any insect (except possibly butterflies) but the true bugs belong to the order Hemiptera and are one of the most diverse groups of insects. Although often confused with beetles, most of which are of similar size, they can be distinguished by their distinctive wings and mouthparts which are designed to suck liquids – either of plant or animal origin depending on the species concerned – and most of all by their totally different life cycle.

Saturday, 23 March 2013

Now on show in the newly redecorated Bug World is a pair of Lesser Goliath Beetles Chelorrhina polyphemus. The generic name is a bit uncertain – some authorities now put them in Mecynorrhina. A Cetoniine scarab beetle, they originate from Central Africa rainforest and have a very similar life cycle to the Purple Jewel beetles and Hercules beetles I wrote about in earlier posts.

One of the larger scarab beetles, males of this species can reach nearly 8 cm long, with females around 4cm maximum. Aside from size, the males can be distinguished by the ‘antlers’ on the head, which are not as well developed as those of the Rhinoceros beetle but are still useful in fighting with other males, for which reason males need to be kept separately in captivity.

M.polyphemus female

The adults can live many months, and the complete life cycle from egg to death of adult is around a year, although development time for the larvae is shorter at higher temperatures. Eggs are laid in the soil after the female digs down deep into the substrate, and the larvae feed on decomposing wood, decaying leaves, and anything else with some nutrient content. Although not predatory, they could be cannibalistic if hungry and crowded, and to protect themselves they craft a quite solid cocoon incorporating wood particles before pupating.

Although brightly coloured, the metallic green of their wings is quite effective camouflage amongst rainforest foliage. They are not especially secretive, instead relying on their wings (they are good fliers) and well-armoured bodies to protect themselves. Large beetles like these do not have many predators as adults, although the larvae are favoured foods for many terrestrial mammals and reptiles, and their main threat is probably parasitic wasps, many of which are species-specific, although I have not been able to find much information on what parasitizes this particular species.

In captivity they are slightly harder to raise than the smaller species, but are well within the range of a home hobbyist. Basic rearing conditions are a suitably large container of rotting wood and dead leaves maintained at around 25 degrees for the larvae, supplemented with dry dog food to add nutrients. Adults feed on fruit such as banana, but need a covered container to prevent escape.

Monday, 11 March 2013

Growing to around 3cm at the most, compared to other beetles Polposipus herculeanus is not in fact especially large, but still an impressive member of the invertebrate fauna of Fregate island in the Seyechelles. A tenebrionid, it belongs to the same family as the more famous mealworm beetle, but unlike its relative it has a highly restricted range, being known today only from its namesake island.

Tuesday, 5 March 2013

Currently on show in Bug World is a large and spectacular ground beetle, the Six-Spotted ground Beetle Anthia sexguttata. Unlike the previous species in the series, they are most definitely carnivorous, and have impressive mandibles as armament.

Tuesday, 26 February 2013

The Purple Jewel Beetles I wrote about last week belong to the subfamily Cetoniinae of the Scarabeidae, the scarab beetles. Related to them, but far larger (they include the largest and heaviest of all insects) are the giant Rhinoceros and Stag beetles of the related subfamily Dynastinae. Keeping beetles of all sizes is a popular hobby in Japan, and as a result a surprising number of these magnificent insects are now bred in captivity. The whole group of Rhinoceros beetles all over the world are marked by the extravagant head ornaments of the males, which use their decorations in fights over access to females. Part of the reason they are popular in Japan is that contests are staged between pet beetles like real life versions of Pokemon.

Tuesday, 19 February 2013

According to legend, when the great biologist JBS Haldane was once asked what his studies had taught him about God, he replied that he had an inordinate fondness for beetles. There are actually several variants of the quote, largely because JBS repeated the story on numerous occasions (it was too good to throw away). Personally, I take issue with the inordinate part, as beetles represent the largest of all insect groups and have diversified immensely in size, habitat, and lifestyle, with in all probability well over 400,000 different species. Just because people mostly ignore them (unless they eat our crops) is no reason God has to share our prejudice.

Saturday, 9 February 2013

The first time I saw an Aye-Aye was at Jersey Zoo (now the Durrell Wildlife Conservation Trust). I had gone into the nocturnal house and was trying to see it clearly when it suddenly loomed up in front of me. Even though I had seen photos, I still took a step back – it is so indescribably weird looking. I am not surprised in the least that it figures prominently in Malagasy folklore as an animal of ill omen (even though it is totally harmless) – any people who had Aye-Ayes roaming their back gardens after dark would do the same.

Monday, 4 February 2013

Across the world, many different animal lineages have produced groups specialised in consuming the leaves and culms of the local forms of bamboo. Most famously of course the giant panda is a bamboo specialist, and so to a lesser extent is the red panda, but several primates have specialised in bamboo – in fact some populations of mountain gorilla feed almost exclusively on bamboo. In Madagascar a group of otherwise unremarkable lemurs have become bamboo specialists, and one population of these has gone even further and become the only known primate to specialise in feeding on water reeds. This is the Lac Alaotra Gebtle Lemur, known locally as the bandro, Hapalemur (griseus) alaotrensis.

Monday, 28 January 2013

Not as familiar to the general public as many of their relatives, scattered through the forests of Madagascar are a multiplicity of forms of what might perhaps be determined the typical lemurs, Eulemur. As with the rest of Madagascar’s wildlife, increased study in recent years has greatly increased the number of named species, which currently stands at around twelve, possibly more if some subspecies are raised to specific rank.

Thursday, 24 January 2013

Readers may recall that our male Asiatic Lion Kamal died last year. However, before he died he bacame a father for the second time at Bristol, and now the cubs are older the embargo on the press release has been lifted. From the Bristol Zoo website:

Saturday, 19 January 2013

Probably the most well known lemur in the world, and one to be seen in practically all major and many minor zoos, the Ring-Tailed Lemur is in many respects rather unusual compared to its relatives. For one thing, although it can climb and leap from tree to tree with ease, it spends much of its time on the ground, a lifestyle otherwise known only among the extinct baboon lemurs, Archaeolemur. In diet it is unspecialised, feeding on fruits, seed pods, terrestrial plants and flowers, fungi, and a variety of insects and small vertebrates, although its favourit food in most of its range is the tamarind tree. This is probably why it does well in captivity – the range of foods it is adapted to eat means that feeding them on food obtained from cultivated crops and artificial diets will keep them in good condition, even before more scientific formulations were developed.

Friday, 11 January 2013

Perhaps least changed from the stock ancestral to all other lemurs, the mouse lemurs or Cheirogaleids are a diverse group of small to extremely small, nocturnal primates. They include the smallest of all lemurs, the Pygmy Mouse Lemur Microcebus myoxinus, and here at Bristol we have a succeful family group of the almost equally minute Grey Mouse Lemur, Microcebus murinus.

Friday, 4 January 2013

One of the most important groups of primates to be seen at Bristol or any other zoo is the lemurs of Madagascar. Confined only to that island (with human introduction of one species to the Comores) they represent a unique radiation of primates in isolation from other primate species, a process which has been going on for many millions of years, possible even before the extinction of the dinosaurs. After thriving on the islands for all that time, around 2000 years ago they encountered disaster in the form of human colonists (not from nearby Africa, but from clear across the Indian ocean in Indonesia). Since that time, many species have become extinct, and the rest are all highly threatened.

Tuesday, 1 January 2013

As well as the various education and captive breeding programs run from Bristol, the zoo is also involved in several in-country projects all over the world, usually as part of a consortium with other zoos and conservation organisations. Here are some of the projects we are involved in, and links to where you can find out more.

Cameroon

orphaned chimps at AAA

The bushmeat trade in Africa is one of the major threats to Africa’s wildlife. Contrary to what is commonly believed, this is not a subsistence-level practise, rather in many cases a supply of expensive wild meat to the cities for high-end purchasers. As a result of the hunting of primates especially, a large number of orphans result. These tend to be kept for a while and then eaten later, but with improved law enforcement many are now confiscated and go to various rescue centres. Since 1997 Bristol has been working with the charity Ape Action Africa, providing veterinary support, education training, and publicity for support and care, with possible eventual rehabilitation, at the Mefou National Park. There are already a small number of regular visitors, and the potential for increasing eco-tourism is certainly there.